(a)(i) Primary cell defects:
— Polarization
— Local action Polarization
— This is due to hydrogen bubbles covering the positive electrode (copper plate). Local action
— This is due to the use of impure zinc or the gradual wearing away of the negative electrode zinc plate.
(ii) Advantages of secondary cell over a primary cell:
— a secondary cell can be recharged while primary cell cannot.
— secondary cell can supply current for a longer period while the primary cell has a short life-span.

(b)


(c)(i) The internal resistance of the dry cells is much larger than that of the accumulators, hence accumulators will produce larger currents needed to start the engine.
(ii)

	Positive terminal	Negative terminal	Electrolyte
Leclanche cell	Carbon rod	Zinc rod	Ammonium chloride (NH\(_4\)
charged lead acid accumulator	Lead (IV) oxide or Lead peroxide	Lead	Lead Tetra oxo-sulphate (VI) acid (H\(_2\)SO\(_4\))